Joint and dowel structure for roadways



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Dec. 27, 1938. L. B. JOHNSON JOINT AND DOWEL STRUCTURE FOR ROADWAYS Filed Jan. 25, 1938 Patented Dec. 27, 1938 UNITED STATES PATENT OFFICE .y

JOINT ANDDOWEL STRUCTURE FOR ROADWAYS 3 Claims.

The present invention relates to a combined joint and load-transfer assembly for use in roadways, pavements, and the like, and more particularly to such an assembly in concrete roadways 5 constituting a positive contraction joint and loadtransfer device.

' One of the objects of the invention is the construction of a joint having a dowel assembly associated therewith for use in a concrete roadway or the like, said assembly serving to hold the joint normal to the sub-grade of the roadway with the dowels parallel to each other and likewise parv allel to the finished grade.

,Another purpose of the invention is the building of a unitary dowel assembly and contraction joint for use in a concrete roadway, the unitary device having means for anchoring and properly positioning the joint and assembly in the roadway. j

'Still another airis the formation of a unque joint for use in concrete pavements and the like.

The invention of the instant application is an improvement on the load-transfer device shown in my prior Patent No. 2,104,866, issued January 1l, 1938.

Other aims and objects will be apparent to those skilled in the art from the description of the invention hereinafter appearing, when read in conjunction with" the appended drawing forming a part hereof, and to which reference is now made and in which:

Fig. 1 is a plan view of the novel combined v joint and dowel assembly prior to its insertion in a concrete pavement or roadway, and showing the relative position of the anchoring means.

Fig. 2 is a'front elevational view of the device shown in Flg. 1.

Fig. 3 is a view partly in section and partly in elevation showing the manner of mounting the combined joint and dowel assembly in a. concrete roadway, and. i

Fig. 4 is a plan view oi one ofthe anchoring means or brace rods.

In my prior Patent No. 2,104,866, referred to above, there is disclosed a load-transfer device for roadways to be used in conjunction with an expansion joint or expansion material. The joint or material forms no integral part of the device disclosed in the aforementioned patent. The instant invention, on the other hand, contemplates a novel jo nt forming an integral part of the device and comprises a metal plate welded to the top of the dowels and in line with the upright or vertical portion of the angle iron resting in the u sub-grade of the roadway forming a supporting member. This arrangement constitutes a loadtransfer device and, in addition thereto, a positive contraction joint. Means are provided for permanently anchoring the device in the roadway prior to the pouring of the concrete.

Referring now" to the drawing the reference character A designates the combined joint and dowel assembly which comprises an elongated supporting member I0 in the form of an angle iron, said angle iron having a horizontal portion II and a vertical portion I2 at right angles thereto.

A series of similar dowel pins or bars are designated by the reference numeral I3, each pin or bar being characterized by a horizontal section I4 and a downwardly extending curved section I 5, the latter projecting from said horizontal section I4 and being secured, as by welding 'or the like, to the horizontal and vertical portions II and I2 of the supporting member I0. By reference to Figs. 1 and 2 of the drawing it will be noted that the downwardly curved portion I5 of each dowel is positioned in a plane angularly disposed with respect to the horizontal and vertical portions II and I2 of the supporting member I0. Also it will be noted that the dowels on the left hand side of the device A are oppositely positioned with respect to the dowels on the right hand side of the device, this is to say, in intersecting planes. Secured to the horizontal portion I4 of each dowel, as by welding or the like, and in alignment with the vertical portion I2 of the supporting member I0, is a metal plate forming; a. joint J. A plurality of washers I'I are Welded or otherwise secured, in spaced relation, to the horizontal portion II of the supporting member I0 adjacent the free edge thereof and extending therebeyond and a plurality of similar washers I8, in vertical alignment with the washers I l, are secured, also by welding or the like, to the horizontal portion I4 of a plurality of dowels I3 to one side thereof and forwardly of the joint J. By reference to Fig. 3 of the drawing it will be noted that the sub-grade of the road is designated by the reference character G and the concrete which hardens into slabs by the reference character C. In assembling the device for use the combined joint and assembly A is positioned on the sub-grade G of the roadway with the joint J normal thereto. A plurality of pins I9 are then inserted through the aligned washers Il and I8 and driven into sub-grade G to position the device on the surface of the latter. The pins I9 adjacent the opposed ends of angle iron I0 have associated therewith anchoring rods or braces 20. Each of the latter is equipped with end washers 2l and 22 welded or otherwise secured to the ends thereof. The ends of pins I9 pass through the washer 2I while the other washer 22 receives an anchoring pin 23, the latter being driven into the sub-grade G of the roadway. When the concrete C is poured it will entirely enclose the combined joint and dowel assembly A, and the concrete is built up to form the roadway, the surface of which is designated by the reference numeral 25.

When the concrete has been poured on both sides of the joint J a plane of weakness is set up by the vertical leg I2 of the supporting member I0 and the metal plate forming the joint J welded to the top of the dowel members I3. The concrete as it hardens shrinks and cracks between the upright leg I2 of the supporting or angle member I0 and the metaljoint J forming an irregular crack 26. This crack provides, through friction, additional load transfer value.

From the above description it will be apparent that the entire assembly A is held in place by the brace rods 20 and the locking pins I9 and 23. The locking pins and brace rods hold the unit in its desired true position and in which position it is adapted to withstand the working loads imposed thereon during the laying of the roadway. The brace rods resist the disturbing forces exerted by the finishing machine' andl li'old the dowel bars and contraction plate intheir'correct position at all times. The brace rods and anchoring pins, as will be understood, remain in the concrete C and provide reinforcement for the dowel and joint assembly, the latter being very effective in providing an eilicient joint of great load transfer value, as Well as of great strength and rigidity.

Obviously the invention is susceptible to more or less modification than what has been shown and described, and desirable changes may suggest themselves to those skilled in the art without departing from the spirit of the invention. It is contemplated to cover all such modifications and to be limited in this respect only as may be necessary by the scope of the claims hereto appended.

What I claim isr- 1. A paving construction unit comprising a supporting member having a vertical portion, a plurality of dowels positioned at spaced intervals extending above said member and transversely thereof, said dowels each having an extension rigidly connected to said member, and a contraction member secured to said dowels in alignment with and spaced from said vertical portion.

2. A paving construction unit comprising a supporting member having a vertical portion, a plurality of dowels positioned at spaced intervals transverselyabove said member, each dowel having means securing same to the latter, a plate secured to the upper surface of the dowels in vertical alignment with said portion, means secured to said dowels and supporting member for anchoring the unit, said means comprising aligned Washers, pins passing through said washers, and brace rods adjacent the opposed ends of said supporting member.

3. A combined load transfer and joint assembly comprising an angle supporting member having a vertical portion, a plurality of spaced dowels secured to and extending transversely above said member, and a contraction plate rigidly mounted on the upper surface of said dowelsin alignment with said vertical portion.

LOUISB. JOHNSON. 

